Revert "hwdb: add a touchpad hwdb"

Revert "hwdb: add a touchpad hwdb"

The main purpose of this hwdb was to tag touchpads that have the physical
trackstick buttons wired to the touchpad (Lenovo Carbon X1 3rd, Lenovo *50
series).  This hwdb is not required on kernels 4.0 and above, the kernel now
re-routes button presses through the trackstick's device node. Userspace does
not need to do anything.

See kernel commit cdd9dc195916ef5644cfac079094c3c1d1616e4c.

This reverts commit 001a247324b44c0e0b8fdba41a6fc66e7465b8b6.